Machines, for example backhoes, excavators, graders, and loaders, commonly have a power linkage that is movable to control the motion of a connected tool such as a bucket, a blade, a hammer, or a grapple. When equipped with a single tool, these machines become specialized machines that are primarily used for a single purpose. Although adequate for some situations, the single purpose machines can have limited functionality and versatility. A tool coupler assembly can be used to increase the functionality and versatility of a host machine by allowing different tools to be quickly and interchangeably connected to the power linkage of the machine.
Tool coupler assemblies are generally known and include a frame connected to the linkage of a machine, and hooks or latches that protrude from the frame. The hooks of a tool coupler assembly engage corresponding pins of a tool to thereby connect the tool to the linkage. To help prevent undesired disengagement of the hooks from the pins, tool coupler assemblies can be equipped with a hydraulic piston that locks the hooks in place against the pins.
When connecting or disconnecting a tool to a host machine, precautions should be taken to help ensure the procedure is performed properly. For example, the tool should be in a desired resting position before decoupling is performed so that the tool does not move in an unexpected manner after the decoupling. In addition, fluid provided to the hydraulic piston of the tool coupler assembly should be at a pressure that allows proper operation of the tool coupler assembly without causing damage to the assembly.
U.S. Pat. No. 8,281,506 to Stefek et al. (the '506 patent) describes a tool coupler assembly that includes a frame connected to a linkage of a machine, and hooks or latches that protrude from the frame. The hooks of the tool coupler assembly frame engage corresponding pins of a tool to thereby connect the tool to the linkage. A tool coupler hydraulic piston locks the hooks in place against the pins. The tool coupler assembly of the '506 patent includes an offset between the pins on the tool and the point on the frame of the tool coupler assembly where a force is applied to pivot the tool about one of the pins. This offset may add additional tip radius to the machine, and may reduce the overall breakout forces seen at the bucket tips. The frame of the tool coupler assembly in the '506 patent may also add weight and additional cost for the tool coupler assembly.
The tool coupler assembly of the present disclosure addresses one or more of the characteristics set forth above and/or other problems of the prior art.